Beacon

The tags defined on this page will render in various nautical charts.
This page defines values for the "seamark:type" tag for beacons and their category attribute tags.

Types

A beacon is a prominent, specially constructed object forming a conspicuous mark as a fixed aid to navigation or for use in hydrographic surveys.

Type

S100 Code

seamark:type

Definition

Example Renderings

Photo

Cardinal Beacon

BCNCAR

beacon_cardinal

A cardinal beacon is used in conjunction with the compass to indicate where the mariner may find the best navigable water. It is placed in one of the four quadrants (North, East, South and West), bounded by inter-cardinal bearings from the point marked.

Isolated Danger Beacon

BCNISD

beacon_isolated_danger

An isolated danger beacon is a beacon erected on an isolated danger of limited extent, which has navigable water all around it.

Lateral Beacon

BCNLAT

beacon_lateral

A lateral beacon is used to indicate the port or starboard hand side of the route to be followed. They are generally used for well defined channels and are used in conjunction with a conventional direction of buoyage.

Safe Water Beacon

BCNINB

beacon_safe_water

A safe water beacon is a prominent specially constructed object forming a conspicuous mark as a fixed aid to navigation or for use in hydrographic surveys.

Special Purpose Beacon

BCNSPP

beacon_special_purpose

A special purpose beacon is primarily used to indicate an area or feature, the nature of which is apparent from reference to a chart, Sailing Directions or Notices to Mariners (UKHO NP 735, 5th Edition). Beacon in general: A beacon whose appearance or purpose is not adequately known.

When top-marks, retro reflectors and/or lights are fitted to these marks, they are encoded as separate objects. Note that such top-marks are encoded as separate "topmark" (TOPMAR) objects). Beacons may also have lights and if such lights are fitted they are encoded as separate "light" (LIGHTS) objects.

Categories

Cardinal Beacons

Cardinal beacons are always painted in yellow and black horizontal bands and their distinctive double cone top-marks are always black.

Quadrant bounded by the true bearing NW-NE taken from the point of interest it should be passed to the north side of the mark.

black;yellow

2 cones up

East

east

Quadrant bounded by the true bearing NE-SE taken from the point of interest it should be passed to the east side of the mark.

black;yellow;black

2 cones base together

South

south

Quadrant bounded by the true bearing SE-SW taken from the point of interest it should be passed to the south side of the mark.

yellow;black

2 cones down

West

west

Quadrant bounded by the true bearing SW-NW taken from the point of interest it should be passed to the west side of the mark.

yellow;black;yellow

2 cones point together

Isolated Danger Beacons

There are no categories of Isolated Danger Beacons. The default colours and topmarks are:

seamark:beacon_isolated_danger:colour

seamark:beacon_isolated_danger:colour_pattern

seamark:topmark:shape

seamark:topmark:colour

black;red;black

horizontal

2 spheres

black

Lateral Beacons

There are two international buoyage regions, A and B, between which lateral marks differ. The buoyage region is encoded using the separate attribute "system" (MARSYS).
Lateral beacons and their topmarks are always painted in red, green or red & green horizontal bands.

Category (CATLAM)

beacon_lateral:category

Definition

seamark:beacon_lateral:colour

[seamark:beacon_lateral:colour_pattern=horizontal]

seamark:topmark:shape

Port-hand Beacon

port

Indicates the port boundary of a navigational channel or suggested route when proceeding in the 'conventional direction of buoyage'.

IALA-A: red, IALA-B: green

cylinder

Starboard-hand Beacon

starboard

Indicates the starboard boundary of a navigational channel or suggested route when proceeding in the 'conventional direction of buoyage'.

IALA-A: green, IALA-B: red

cone, point up

Preferred Channel to Starboard Beacon

preferred_channel_starboard

At a point where a channel divides, when proceeding in the 'conventional direction of buoyage', the preferred channel (or primary route) is indicated by a modified port-hand lateral mark.

IALA-A: red;green;red, IALA-B: green;red;green

cylinder

Preferred Channel to Port Beacon

preferred_channel_port

At a point where a channel divides, when proceeding in the 'conventional direction of buoyage', the preferred channel (or primary route) is indicated by a modified starboard-hand lateral mark.